The brain is among the organs most affected by hypertension. An estimated 80 million people in the United States suffer from this disease. Hypertension is the second most important risk factor for vascular problems in the brain that lead to dementia and strokes. Age is the number one factor.
Currently, dementia affects between 30 and 40 million people worldwide. Due to an aging population, this number is expected to triple by 2050.
Dr. Biller is a member of the multidisciplinary panel of experts, and recently wrote an article that was published in the heart association journal Hypertension. He is of the opinion that high blood pressure in middle age is a potential risk factor for Alzheimer’s and can lead to impaired cognition.
There is reliable evidence that altered cognitive function in both middle age and late life (65 to 84) is preceded by chronic high blood pressure during middle age (40 to 64). Memory, speed of processing and executive function are some of the cognitive abilities that are affected. Executive functions include the ability to make decisions, organize thoughts and manage time.
It is not so clear what the effect of high blood pressure in late life is. Some researchers suggest it may improve cognition, but others feel that it is harmful. The expert panel points out that the varying conclusions highlights that recommending uniform levels of blood pressure across a person’s lifespan is complex.
It has been demonstrated that high blood pressure causes damage to the brain’s blood vessels including hardening of the arteries (atherosclerosis). The observational studies used also shows that this leads to reduced blood flow to brain cells. On the other hand, evidence from clinical trials concluding that treating high blood pressure improves cognition is not conclusive.
The panel reviewed the available studies, but ultimately concluded there is not enough data to make recommendations based on evidence. They do however feel that careful treatment of high blood pressure is justified to safeguard vascular health and as a result, brain health. The panel does however stress that the patient’s individual characteristics and goals of care should be taken into account when embarking on any treatment.